Plate Fixation of Hamate Fractures in Fourth and Fifth Carpometacarpal Fracture Dislocations.

Traumatic dislocations of the fourth and fifth metacarpals, in conjunction with dorsal hamate fractures, are a common entity that can lead to the instability of the fourth and fifth carpometacarpal (CMC) joints. The fracture of the hamate, usually in a coronal dorsal shear configuration, can lead to the dorsal subluxation of the hamatometacarpal joint. Open reduction and internal fixation of the hamate bone with a dorsally applied buttress plate can re-establish a stable and congruent joint surface and anatomically align the articular surfaces of the small and ring finger CMC joints. We present a technique of internal fixation of the hamate to facilitate the reduction of the hamatometacarpal joints. Using a dorsal approach centered over the fourth and fifth CMC joints, the joint surfaces are directly visualized and subsequent fixation of the hamate is performed using a 1.3-mm T-plate to securely buttress its articular surface. This technique presents an approach to the multifaceted injury pattern of fourth and fifth CMC dislocations associated with a hamate fracture.

A Biomechanical Comparison of Fixation Techniques in Metacarpal Shaft Fractures.

Background Typically, metacarpal shaft fractures are treated with closed reduction percutaneous pinning, intramedullary nails, or plate fixation. Recently some surgeons have begun using intramedullary headless compression screws. Questions/Purposes The purpose of this study was to compare intramedullary screw fixation to K-wire fixation, which is the standard of care in a transverse metacarpal midshaft fracture, using a cadaveric model. Our hypothesis was that intramedullary screw fixation would have a biomechanical advantage (higher stiffness and peak load to failure) when compared with dual Kirschner wire fixation of transverse metacarpal shaft fractures. Methods Four-point bend testing was performed to compare stiffness and failure load values of seven paired 2nd and 3rd metacarpals instrumented with headless intramedullary compression screw fixation or Kirschner wire fixation. Similar testing was performed on 14 unpaired 4th metacarpals. Results There was no significant difference in peak load ( p = 0.60) or stiffness ( p = 0.85) between fixation groups for the 2nd and 3rd instrumented metacarpals. For the instrumented 4th metacarpals, there was no significant difference in peak load ( p = 0.14), but the stiffness was significantly greater ( p = 0.01) for the compression screw group compared with the Kirschner wire fixation. Conclusions/Clinical Relevance In this study, the load to failure was not different between the two fixation methods and likely both techniques can sustain physiologic loads needed for rehabilitation. The greater stiffness in the 4th metacarpal compression screw group may be related to the smaller canal morphology than in the 2nd and 3rd metacarpals. Larger diameter screws may be needed to obtain a better fit particularly in the 2nd and 3rd metacarpals.

Biomechanical Comparison of Dart-Throw Motions after Partial Wrist Fusions.

Background Multiple partial wrist fusions exist for the management of arthritic disease. Limited information is available on their effect on wrist range of motion in the dart-throwing direction of wrist motion, even though it is used in most activities of daily living. Purpose The purpose of this study was to measure the retained motion for different orientations of dart-throwing motion for seven different partial wrist fusions and proximal row carpectomy (PRC). Methods Eight fresh frozen right cadavers were tested with the wrist intact and followed simulated fusions. Fusions were performed using an external fixation technique and included scaphocapitate, scapholunate (SL), capitolunate, radiolunate, radioscapholunate, scaphotrapeziotrapezoid, 4 corner fusion, and PRC. Results In the intact wrist, the average arc of wrist motion with the wrist oriented at 20 degrees away from the flexion-extension axis was significantly larger than at any other orientation of motion. All partial wrist fusions and the PRC had significantly smaller average dart-throw arc of motion compared with intact at an orientation 20 and 25 degrees away from flexion-extension. The SL fusion provided a significantly larger arc of motion than most of the other fusions at most orientations. Conclusion/Clinical Relevance This study provides a comprehensive compilation of the range of motion in a functional plane, "the dart-throw motion," for limited wrist fusions and PRC. These data provide the clinician with important information that can be used to educate patients regarding expectations after surgery.

On the causes of Arctic sea ice in the warm Early Pliocene.

Scattered and indirect evidence suggests that sea ice occurred as far south as the Iceland Sea during the Early Pliocene, when the global climate was warmer than present. However, conclusive evidence as well as potential mechanisms governing sea ice occurrence outside the Arctic Ocean during a time with elevated greenhouse gas concentrations are still elusive. Here we present a suite of organic biomarkers and palynological records from the Iceland Sea and Yermak Plateau. We show that sea ice appeared as early as ~4.5 Ma in the Iceland Sea. The sea ice either occurred seasonally or was transported southward with the East Greenland Current. The Yermak Plateau mostly remained free of sea ice and was influenced dominantly by Atlantic water. From ~4.0 Ma, occurrence of extended sea ice conditions at both the Yermak Plateau and Iceland Sea document a substantial expansion of sea ice in the Arctic. The expansion occurred contemporaneous with increased northward heat and moisture transport in the North Atlantic region, which likely led to a fresher Arctic Ocean that favors sea ice formation. This extensive sea ice cover along the pathway of the East Greenland Current gradually isolated Greenland from warmer Atlantic water in the Late Pliocene, providing a positive feedback for ice sheet expansion in Greenland.

Technique of Dynamic Flexor Digitorum Superficialis Transfer to Lateral Bands for Proximal Interphalangeal Joint Deformity Correction in Severe Dupuytren Disease.

Pseudo-boutonniere deformity is an uncommon complication from long-standing proximal interphalangeal (PIP) joint contracture in Dupuytren disease. Prolonged flexion contracture of the PIP joint can lead to central slip attenuation and resultant imbalances in the extensor mechanism. We present a technique of flexor digitorum superficialis (FDS) tendon transfer to the lateral bands to correct pseudo-boutonniere deformity at the time of palmar fasciectomy for the treatment of Dupuytren disease. The FDS tendon is transferred from volar to dorsal through the lumbrical canal and sutured into the dorsally mobilized lateral bands. This technique presents an approach to the repair of pseudo-boutonniere deformity in Dupuytren disease.

Dynamic Functional Assessment of Hand Motion Using an Animation Glove: The Effect of Stenosing Tenosynovitis.

BACKGROUND: The aim of the present study is to determine whether an animation glove can be utilized to provide a reliable and reproducible assessment of dynamic hand function and whether this assessment is altered in the setting of hand pathology. METHODS: Ten subjects without known hand pathology and 11 subjects with known stenosing tenosynovitis were assessed on tasks involving hand function at varied speeds, including forceful and gradual making of a fist and the quick and slow grip of a baseball using an animation glove to record range of motion and measures of velocity (CyberGlove II). RESULTS: In normal subjects, peak extension and flexion velocity of the index and middle finger was highest in the metacarpophalangeal and lowest in the distal interphalangeal; however, the converse was true in the ring finger. In those subjects with stenosing tenosynovitis, the animation glove was able to detect a triggering event during assessment. Furthermore, there was a significant decrease in the maximum velocity of the proximal interphalangeal joint observed with the slow fist task in both flexion and extension (55%, P < .01) in the affected hand when compared with the unaffected hand. CONCLUSIONS: The CyberGlove II can be utilized in the dynamic functional analysis of the hand and is able to detect a triggering event in subjects with known stenosing tenosynovitis. Those subjects demonstrate a significant decrease in maximum velocity in slow fist tasks, highlighting the need for comprehensive assessment to ascertain the full extent of functional limitations that can occur in the setting of hand pathology.

Techniques of Force and Pressure Measurement in the Small Joints of the Wrist.

BACKGROUND: The alteration of forces across joints can result in instability and subsequent disability. Previous methods of force measurements such as pressure-sensitive films, load cells, and pressure-sensing transducers have been utilized to estimate biomechanical forces across joints and more recent studies have utilized a nondestructive method that allows for assessment of joint forces under ligamentous restraints. METHODS: A comprehensive review of the literature was performed to explore the numerous biomechanical methods utilized to estimate intra-articular forces. RESULTS: Methods of biomechanical force measurements in joints are reviewed. CONCLUSIONS: Methods such as pressure-sensitive films, load cells, and pressure-sensing transducers require significant intra-articular disruption and thus may result in inaccurate measurements, especially in small joints such as those within the wrist and hand. Non-destructive methods of joint force measurements either utilizing distraction-based joint reaction force methods or finite element analysis may offer a more accurate assessment; however, given their recent inception, further studies are needed to improve and validate their use.

Evidence for ice-free summers in the late Miocene central Arctic Ocean.

Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth's climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides along Lomonosov Ridge. Removal of younger sediments from steep headwalls has led to exhumation of Miocene sediments close to the seafloor. Here we document the presence of IP25 as a proxy for spring sea-ice cover and alkenone-based summer sea-surface temperatures >4 °C that support a seasonal sea-ice cover with an ice-free summer season being predominant during the late Miocene in the central Arctic Ocean. A comparison of our proxy data with Miocene climate simulations seems to favour either relatively high late Miocene atmospheric CO2 concentrations and/or a weak sensitivity of the model to simulate the magnitude of high-latitude warming in a warmer than modern climate.

Length of hospital stay after hip fracture and risk of early mortality after discharge in New York state: retrospective cohort study.

STUDY QUESTION: Can the length of hospital stay for hip fracture affect a patient's risk of death 30 days after discharge? METHODS: In a retrospective cohort study, population based registry data from the New York Statewide Planning and Research Cooperative System (SPARCS) were used to investigate 188,208 patients admitted to hospital for hip fracture in New York state from 2000 to 2011. Patients were aged 50 years and older, and received surgical or non-surgical treatment. The main outcome measure was the mortality rate at 30 days after hospital discharge. STUDY ANSWER AND LIMITATIONS: Hospital stays of 11-14 days for hip fracture were associated with a 32% increased odds of death 30 days after discharge, compared with stays lasting one to five days (odds ratio 1.32 (95% confidence interval 1.19 to 1.47)). These odds increased to 103% for stays longer than 14 days (2.03 (1.84 to 2.24)). Other risk factors associated with early mortality included discharge to a hospice facility, older age, metastatic disease, and non-surgical management. The 30 day mortality rate after discharge was 4.5% for surgically treated patients and 10.7% for non-surgically treated patients. These findings might not be generalizable to populations in other US states or in other countries. The administrative claims data used could have been incomplete or include inaccurate coding of diagnoses and comorbid conditions. The database also did not include patient socioeconomic status, which could affect access to care to a greater extent in New York state than in European countries. Specific cause of death was not available because few autopsies are performed in this population. WHAT THIS STUDY ADDS: By contrast with recent findings in Sweden, decreased length of hospital stay for hip fracture was associated with reduced rates of early mortality in a US cohort in New York state. This could reflect critical system differences in the treatment of hip fractures between Europe and the USA.Funding, competing interests, data sharing University of Rochester grant from the Clinical Translational Science Institute for statistical analyses used in this work (National Institutes of Health (UL1 TR000042)) and the National Institutes of Health (K-08 AR060164-01A). No competing interests declared. Data may be obtained through SPARCS at https://www.health.ny.gov/statistics/sparcs/access/.

Early Pliocene onset of modern Nordic Seas circulation related to ocean gateway changes.

The globally warm climate of the early Pliocene gradually cooled from 4 million years ago, synchronous with decreasing atmospheric CO2 concentrations. In contrast, palaeoceanographic records indicate that the Nordic Seas cooled during the earliest Pliocene, before global cooling. However, a lack of knowledge regarding the precise timing of Nordic Seas cooling has limited our understanding of the governing mechanisms. Here, using marine palynology, we show that cooling in the Nordic Seas was coincident with the first trans-Arctic migration of cool-water Pacific mollusks around 4.5 million years ago, and followed by the development of a modern-like Nordic Seas surface circulation. Nordic Seas cooling precedes global cooling by 500,000 years; as such, we propose that reconfiguration of the Bering Strait and Central American Seaway triggered the development of a modern circulation in the Nordic Seas, which is essential for North Atlantic Deep Water formation and a precursor for more widespread Greenland glaciation in the late Pliocene.

Distal Radioulnar Joint Reaction Force Following Ulnar Shortening: Diaphyseal Osteotomy Versus Wafer Resection.

PURPOSE: To compare how ulnar diaphyseal shortening and wafer resection affect distal radioulnar joint (DRUJ) joint reaction force (JRF) using a nondestructive method of measurement. Our hypothesis was that ulnar shortening osteotomy would increase DRUJ JRF more than wafer resection. METHODS: Eight fresh-frozen human cadaveric upper limbs were obtained. Under fluoroscopic guidance, a threaded pin was inserted into the lateral radius orthogonal to the DRUJ and a second pin was placed in the medial ulna coaxial to the radial pin. Each limb was mounted onto a mechanical tensile testing machine and a distracting force was applied across the DRUJ while force and displacement were simultaneously measured. Data sets were entered into a computer and a polynomial was generated and solved to determine the JRF. This process was repeated after ulnar diaphyseal osteotomy, ulnar re-lengthening, and ulnar wafer resection. The JRF was compared among the 4 conditions. RESULTS: Average baseline DRUJ JRF for the 8 arms increased significantly after diaphyseal ulnar shortening osteotomy (7.2 vs 10.3 N). Average JRF after re-lengthening the ulna and wafer resection was 6.9 and 6.7 N, respectively. There were no differences in JRF among baseline, re-lengthened, and wafer resection conditions. CONCLUSIONS: Distal radioulnar joint JRF increased significantly after ulnar diaphyseal shortening osteotomy and did not increase after ulnar wafer resection. CLINICAL RELEVANCE: Diaphyseal ulnar shortening osteotomy increases DRUJ JRF, which may lead to DRUJ arthrosis.

A nondestructive, reproducible method of measuring joint reaction force at the distal radioulnar joint.

PURPOSE: To develop a nondestructive method of measuring distal radioulnar joint (DRUJ) joint reaction force (JRF) that preserves all periarticular soft tissues and more accurately reflects in vivo conditions. METHODS: Eight fresh-frozen human cadaveric limbs were obtained. A threaded Steinmann pin was placed in the middle of the lateral side of the distal radius transverse to the DRUJ. A second pin was placed into the middle of the medial side of the distal ulna colinear to the distal radial pin. Specimens were mounted onto a tensile testing machine using a custom fixture. A uniaxial distracting force was applied across the DRUJ while force and displacement were simultaneously measured. Force-displacement curves were generated and a best-fit polynomial was solved to determine JRF. RESULTS: All force-displacement curves demonstrated an initial high slope where relatively large forces were required to distract the joint. This ended with an inflection point followed by a linear area with a low slope, where small increases in force generated larger amounts of distraction. Each sample was measured 3 times and there was high reproducibility between repeated measurements. The average baseline DRUJ JRF was 7.5 N (n = 8). CONCLUSIONS: This study describes a reproducible method of measuring DRUJ reaction forces that preserves all periarticular stabilizing structures. This technique of JRF measurement may also be suited for applications in the small joints of the wrist and hand. CLINICAL RELEVANCE: Changes in JRF can alter native joint mechanics and lead to pathology. Reliable methods of measuring these forces are important for determining how pathology and surgical interventions affect joint biomechanics.

Comparison of image quality and radiation exposure from C-arm fluoroscopes when used for imaging the spine.

STUDY DESIGN: Cadaveric imaging study. OBJECTIVE: We sought to compare the fluoroscopic images produced by 4 different fluoroscopes for image quality and radiation exposure when used for imaging the spine. SUMMARY OF BACKGROUND DATA: There are no previous published studies comparing mobile C-arm machines commonly used in clinical practice for imaging the spine. METHODS: Anterior-posterior and lateral images of the cervical, thoracic, and lumbar spine were obtained from a cadaver placed supine on a radiolucent table. The fluoroscopy units used for the study included (1) GE OEC 9900 Elite (2010 model; General Electric Healthcare, Waukesha, WI), (2) Philips BV Pulsera (2009 model; Philips Healthcare, Andover, MA), (3) Philips BV Pulsera (2010 model; Philips Healthcare, Andover, MA), and (4) Siemens Arcadis Avantic (2010 model; Siemens Medical Solutions, Malvern, PA). The images were then downloaded, placed into a randomizer program, and evaluated by a group of spine surgeons and neuroradiologists independently. The reviewers, who were blinded to the fluoroscope the images were from, ranked them from best to worst using a numeric system. In addition, the images were rated according to a quality scale from 1 to 5, with 1 representing the best image quality. The radiation exposure level for the fluoroscopy units was also compared and was based on energy emission. RESULTS: According to the mean values for rank, the following order of best to worst was observed: (1) GE OEC > (2) Philips 2010 > (3) Philips 2009 > (4) Siemans. The exact same order was found when examining the image quality ratings. When comparing the radiation exposure level difference, it was observed that the OEC was the lowest, and there was a minimum 30% decrease in energy emission from the OEC versus the other C-arms studied. CONCLUSION: This is the first time that the spine image quality and radiation exposure of commonly used C-arm machines have been compared. The OEC was ranked the best, produced the best quality images, and had the least amount of radiation.

Analysis of radiation exposure to the orthopaedic trauma patient during their inpatient hospitalisation.

PURPOSE: There has been considerable concern regarding radiation exposure to both the patient and treating surgeon and the possible risk of resulting malignancy. We sought to analyse the total effective dose of radiation that a cohort of orthopaedic trauma patients are exposed to during their inpatient hospitalisation and determine risk factors for greater exposure levels. METHODS: Following approval from the Institution Review Board, a search was conducted of a level I trauma centre database for radiation exposures to patients over a 1 year period. Patients were included if they had an ICD-9 code from 805 to 828, indicating a fracture involving the trunk (805-811) or extremities (812-828). We compared the total effective radiation dose in various injury patterns as well as those considered to be polytrauma patients to those who were not according to their injury severity score (ISS). RESULTS: The records of 1357 trauma patients were available for review. The average patient age was 40.6 years and the mean ISS was 14.1. The average effective radiation dose for all patients during their hospitalisation was 31.6 mSv. There was a statistically significant difference in radiation exposure between patients with an ISS greater than 16 (48.6 mSv) versus those with an ISS equal to or less than 16 (23.5 mSv), p<0.001. Patients with spine trauma can be expected to get more than 15 mSv more radiation than non-spine patients, p<0.001. Extremity injuries received the least amount of radiation, spine only patients were next, then finally spine and extremity injury patients had the greatest exposures. Having a spine fracture, a pelvic fracture, a chest wall injury, or a long bone fracture were all risk factors for having more than 20 mSv of effective dose exposure. Patients under the age of 18 years did receive less radiation than the remainder of the cohort, p<0.001. CONCLUSIONS: The average orthopaedic patient receives a total effective radiation dose of more than 30 mSv, much greater than is considered acceptable as a recommended permissible annual dose by the International Commission on Radiological Protection (20 mSv). These findings indicate that the average trauma patient (in particular those with polytrauma or fractures involving the spine, pelvis, chest wall, or long bones) is exposed to high levels of radiation during their inpatient hospitalisation. The treating physicians of such patients should take into consideration the large amounts of radiation their patients receive just during their initial hospitalisation, and be prudent with the ordering of imaging studies involving radiation exposure.

1-Phenyl-1,2-cyclohexadiene: generation, interception by activated olefins, dimerisation and trimerisation.

Four possible precursors of 1-phenyl-1,2-cyclohexadiene (2) were examined, namely, 6,6-dibromo-1-phenylbicyclo[3.1.0]hexane, (1alpha,5alpha,6alpha)-6-bromo-6-fluoro-1-phenylbicyclo[3.1.0]hexane, 1-bromo-2-phenylcyclohexene and 1-bromo-6-phenylcyclohexene. All four compounds could be converted into 2, as demonstrated by the products of the interception of 2 with activated olefins. Styrene, 1,1-diphenylethene, indene, furan and 2,5-dimethylfuran were employed as such. Whereas the first three gave [2+2] cycloadducts of 2, the last two provided one [4+2] cycloadduct each. To create the [2+2] cycloadducts, the pi bond of 2 that is more remote from the phenyl group reacted, whereas the pi bond of 2 conjugated with the phenyl group exclusively produced the [4+2] cycloadducts. The generation of 2 in the absence of a trapping reagent brought about relatively good yields of a dimer or a trimer of 2 depending on the mode of the liberation of 2. Being derivatives of triphenylene, the dimer as well as the trimer have unusual structures, thereby indicating that a phenyl group is participating in the formation of these compounds. The most surprising structure of the trimer was elucidated by X-ray crystal diffraction. As to the mechanisms, diradical intermediates are proposed both for the cycloadditions and for the dimerisation. The initial steps of the latter seem to proceed also in the trimerisation.

Acute myelogenous leukemia as the cause of a nonhealing infection in a 10-month-old infant.

The treating podiatric physician should consider underlying malignant disease when evaluating a child with any slowly healing or nonhealing infection involving the lower extremity. This article reports on an infant who was treated for suspected osteomyelitis involving his right fifth toe that did not improve with standard surgical, medical, and antibiotic treatments. He was later diagnosed as having acute myelogenous leukemia.

Pediatric longitudinal epiphyseal bracket: Review and case presentation.

The longitudinal epiphyseal bracket is a rare deformity affecting the long and short bones of the hands and feet, creating an aberration in growth. The deformity is present in 2% to 14% of congenital hand and foot deformities, with 11% of all cases found in the great toe. Ultrasound may then be used to confirm the diagnosis. Radiographs usually show the presence of a bracket epiphysis once there is some ossification, but until then, the radiographs can appear normal. With the use of ultrasound, a suspected preossified bracket can be visualized and can establish the diagnosis. The purpose of this article is to present such a case with a preossified epiphyseal bracket of the great toe. The child presented initially with unremarkable x-rays, but the diagnosis was made with clinical suspicion and use of ultrasound. After surgical resection of the brackets, there was progressive improvement in the short-term follow-up. Long-term follow-up is essential until skeletal maturity, and, if the deformity persists, further surgical care may need to be implemented.

Melorheostosis in a pediatric patient.

Melorheostosis is a nonhereditary and uncommon condition that can affect both adults and children. It can appear on radiographs as increased sclerosis on bones of the upper and lower extremities and may mimic other bony conditions such as osteopoikilosis, osteopetrosis, arthrogryposis multiplex congenita, and osteopathia striata. The sclerotic appearance can differ greatly between adults and children. The skin and subcutaneous tissues may be affected by fibrosis, resulting in contractures of joints and limbs that lead to deformities and limb-length discrepancies. This article reviews the literature on melorheostosis and describes a case in a 10-year-old boy.

Cultural competence: serving Latino patients.

Culturally competent strategies are necessary as populations in many countries become increasingly diverse. In the United States, Latinos are the fastest-growing minority group. In this study, the authors interviewed Latino patients and families, collected demographics from 570 patients in pediatric orthopedic practices in California, and conducted population census and literature reviews. Based on these sources of information, the authors identified barriers to health care for Latino pediatric orthopedic patients and propose culturally competent strategies to overcome these barriers. This approach can be applied to other populations so that culturally competent care is available to patients from all ethnic, racial, and cultural backgrounds.